Electrosurgical system and method for operation thereof

Abstract

A supply apparatus for an electrosurgical system as well as an electrosurgical system having a supply apparatus. In addition to a generator, the supply apparatus has a measurement signal source that is able to provide a measurement signal (XM) in form of an alternating voltage and/or an alternating current. An impedance parameter (P) resulting from the measurement signal (XM) can be evaluated. A switch device of supply apparatus can be switched between multiple switch conditions (C1-C5). In the different switch conditions (C1-C5) different evaluation functions can be realized by means of the evaluation unit (50). The measurement signal source can apply a measurement signal to a treatment current path (B) at a working connection of supply apparatus as well as to a neutral current path (N) between neutral connections of supply apparatus. In doing so, by means of the measurement signal (XM), treated tissue can be analyzed as well as a contact between neutral electrode and the patient can be checked or monitored.

1 . A supply apparatus for an electrosurgical system comprising:
 at least two neutral connections for a neutral electrode ( 13 ) and at least one working connection (for one working electrode of an electrosurgical instrument respectively,   a generator for providing a generator voltage (UG) or a generator current (IG) at a generator frequency (fg),   a measurement signal source for providing a measurement signal (XM) alternating with a measurement frequency (fm),   a measurement device for measurement of an impedance parameter (P) that describes an impedance (Z 1 , Z 2 ) between two apparatus connections to which the measurement signal (XM) is provided,   a switch device that can be switched between multiple switch conditions (C 1 , C 2 , C 3 , C 4 , C 5 ), which electrically connects the measurement signal source with the two neutral connections and disconnects the measurement signal source electrically from the at least one working connection in a first switch condition (C 1 ) and which electrically connects the measurement signal source with at least one of the working connections in a second switch condition, and   an evaluation unit that is communicatively connected with the measurement device and configured for evaluation of the measured impedance parameter (P).   
     
     
         2 . The supply apparatus according to  claim 1 , comprising a first working connection for connection of a working electrode of a monopolar instrument. 
     
     
         3 . The supply apparatus according to  claim 1 , comprising a first working connection for connection of a first working electrode and a second working connection for connection of a second working electrode of a bipolar instrument. 
     
     
         4 . The supply apparatus according to  claim 1 , wherein the measurement signal source is configured to provide the measurement signal (XM) at multiple measurement frequencies (fm) that are different from one another. 
     
     
         5 . The supply apparatus according to  claim 1 , wherein in the first switch condition (C 1 ) the evaluation unit is configured to check an electrical contact between a neutral electrode connected to the two neutral connections and a patient based on the measured impedance parameter (P). 
     
     
         6 . The supply apparatus according to  claim 1 , comprising a first neutral connection for connection of an electrically conductive first electrode area of a neutral electrode and a second neutral connection for connection of an electrically conducting second electrode area of the neutral electrode. 
     
     
         7 . The supply apparatus according to  claim 1 , wherein in the second switch condition (C 2 ) the evaluation unit is configured to determine, based on the measured impedance parameter (P), a tissue condition and/or a tissue type of tissue with which a working electrode of an electrosurgical instrument connected to the at least one working connection is in electrically conducting contact. 
     
     
         8 . The supply apparatus according to  claim 1 , wherein the switch device disconnects the generator electrically from the measurement signal source in the first switch condition (C 1 ) and in the second switch condition (C 2 ). 
     
     
         9 . The supply apparatus according to  claim 1 , wherein the generator is configured or controlled so that the generator does not provide a generator voltage (UG) or a generator current (IG), if the measurement signal source provides a measurement signal (XM) to the switch device in the first switch condition and/or the second switch condition (C 2 ). 
     
     
         10 . The supply apparatus according to  claim 1 , wherein in the second switch condition (C 2 ) the switch device electrically connects the measurement signal source on one side with the at least one working connection and on the other side with the two neutral connections. 
     
     
         11 . The supply apparatus according to  claim 1 , wherein in the third switch condition (C 3 ) the switch device electrically connects the generator on one side with the at least one working connection and on the other side with the neutral connections. 
     
     
         12 . The supply apparatus according to  claim 11 , wherein in the third switch condition (C 3 ) the evaluation unit is configured to check a first current (I 1 ) at the first neutral connection and a second current (I 2 ) at the second neutral connection created by the generator current (IG). 
     
     
         13 . The supply apparatus according to  claim 11 , wherein in the third switch condition (C 3 ) the switch device electrically connects a frequency-dependent impedance circuit, particularly a parallel oscillating circuit, with the measurement signal source. 
     
     
         14 . The supply apparatus according to  claim 1 , wherein in the third switch condition (C 3 ) the measurement signal source is configured or controlled, so that the measurement signal source creates a measurement signal (XM) at the measurement frequency (fm), which is different from the generator frequency (fg). 
     
     
         15 . The supply apparatus according to  claim 14 , wherein in the third switch condition (C 3 ) the measurement signal source is configured or controlled, so that the measurement frequency (fm) of the measurement signal (XM) varies in a frequency range in order to determine a frequency at which the frequency-dependent impedance circuit comprises an impedance maximum (ZPmax). 
     
     
         16 . The supply apparatus according to  claim 1 , comprising a first working connection and a second working connection, wherein the switch device electrically connects the measurement signal source on one side with the first working connection and on the other side with the second working connection in a fourth switch condition (C 4 ). 
     
     
         17 . The supply apparatus according to  claim 1 , comprising a first working connection and a second working connection, wherein the switch device electrically connects the generator on one side with the first working connection and on the other side with the second working connection and disconnects the measurement signal source from first working connection and from second working connection in a fifth switch condition (C 5 ). 
     
     
         18 . An electrosurgical system comprising the supply apparatus of  claim 1  and further comprising a bipolar instrument or a monopolar instrument.